One way to work on WordPress without having to be on a live server and connected to the net is by carrying a functional (local) copy of your server software (Apache, PHP, MySQL) on your laptop. WLTC has a 2 part instructions to help you do just that. It might also be of interest to know that there is an even more flexible and possibly more efficient way to accomplish this, to have a copy right in your USB stick, Ralph.fm has the “Know How”, check it out!